JPH0557657B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a resist master heat treatment apparatus.

BACKGROUND ART There is an optical method as a method for recording video, audio information, etc. on a recording medium in the form of a disc. This optical method creates a resist master by coating a photoresist on the surface of a glass disk that serves as a base plate and forming a resist layer. Information is recorded using the so-called bit-by-bit method in which a beam flickers in response to video or audio information, etc., and is then developed based on the length of the pits (dents) obtained and their repetition period.

In this method, a resist master is created by applying a photoresist to a glass master which has been cleaned and primed, and then heat-treating (baking) the resist layer.

Conventionally, a hot air circulation oven has been known as an apparatus for heat-treating the resist layer of the resist master. In this hot air circulation oven, the second
As shown in the figure, air (gas) sent by a blower fan 1 is heated by a heater 2, and then sent to a resist master 4 through a filter 3 to heat the resist layer of the master, and The temperature sensor 5 measures the ambient temperature inside the oven, and the heater 2 is driven and controlled based on the measured temperature.

In such conventional devices, heating efficiency is poor because heating is performed by thermal conduction, and the movable part (fan 1)
Since it is installed inside the oven, it has the disadvantage of being susceptible to contamination. Furthermore, the baking temperature is controlled with respect to the ambient temperature, and the difference in the heat capacity of the resist master 4 directly becomes the difference in the baking temperature, resulting in variations in the baking temperature.

Generally, there is a correlation between baking temperature and photoresist sensitivity, such that as the baking temperature increases, the sensitivity of the photoresist decreases. As the sensitivity of the photoresist decreases, the amount of exposure (dose) required to obtain a certain pattern increases, so variations in baking temperature are directly reflected in variations in the pattern, resulting in variations in the quality of the resist master. Put it away.

Summary of the invention The present invention has been made in view of the above points, and
It is an object of the present invention to provide a resist master heat treatment apparatus that has good heating efficiency and can always perform heat treatment at a constant temperature.

The resist master heat treatment apparatus according to the present invention is configured to heat-treat the resist layer of the resist master using far infrared rays, measure the surface temperature of the resist master, and manage the baking temperature based on the measured temperature. .

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which a far-infrared heater 6 is used to bake (heat treat) the resist layer of the resist master 4. As shown in FIG. By using this far-infrared heater 6, heating can be performed by energy conversion by absorption of far-infrared rays, so only the surface of the resist master 4 can be effectively heated, and the infrared absorption of organic solvents etc. in the resist can efficiently heat the resist master 4. It will be possible to bake it. As a result, it is possible to shorten the baking time, approximately one-fifth the baking time compared to the conventional baking method using a hot air circulation oven.
This can be shortened to . Furthermore, it is also possible to shorten the time required to cool down the resist master 4 after baking. In other words, in the case of this device, only the surface of the resist master 4 is heated, so the cooling time from the baking temperature to room temperature can be reduced to about half that of the conventional hot air circulation oven. Become.

A radiation thermometer 7 is provided for measuring, for example, the surface temperature of the resist master 4 undergoing baking in a non-contact manner, and the measurement output of this radiation thermometer 7 is supplied to a controller 8 . The controller 8 always controls the heater drive circuit 9 based on the measurement output of the radiation thermometer 7 so that baking is terminated when the surface temperature of the resist master 4 reaches a certain constant temperature. Since the surface temperature measured by the radiation thermometer 7 is an apparent temperature, the effective values of the emissivity of the resist master 4 and the radiation transmittance along the observation path by the radiation thermometer 7 are determined in advance. By correcting the measurement output of the radiation thermometer 7 based on the obtained data, the surface temperature can be measured more accurately. As a result, the baking temperature can be controlled more accurately, making it possible to create a resist master with stable sensitivity.

In the above embodiment, the radiation thermometer 7 is used as a means for measuring the surface temperature of the resist master 4, but the present invention is not limited to this. It is sufficient if the surface temperature of the master 4 can be measured.

Effects of the Invention As explained above, according to the resist master heat treatment apparatus according to the present invention, heating is performed by energy conversion by absorption of far infrared rays, so heating efficiency is high.
In addition, by controlling the baking temperature by actually measuring the surface temperature of the resist master, the baking temperature can be kept constant regardless of the heat capacity of the resist master, so a resist master with stable sensitivity can be obtained and a high yield can be achieved. become.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a configuration diagram showing a conventional example. Explanation of symbols of main parts, 4...Resist master,
6... Far infrared heater, 7... Radiation thermometer.

Claims (1)

[Scope of Claims] 1. An apparatus for heat-treating a resist layer of a resist master, comprising a far-infrared heater that irradiates far-infrared rays to the resist master, and a measuring means for measuring the surface temperature of the resist master. . A resist master heat treatment apparatus, characterized in that drive control of the far-infrared heater is performed based on the measurement output of the measurement means. 2. The resist master heat treatment apparatus according to claim 1, wherein the measuring means is a radiation thermometer.